Area Forecast Discussion
Issued by NWS Boston, MA

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000 FXUS61 KBOX 062311 AFDBOX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 711 PM EDT MON JUL 6 2015 .SYNOPSIS... WARM AND MUGGY CONDITIONS ARE ANTICIPATED TOMORROW AND WEDNESDAY AS A SERIES OF FRONTS BRINGS SCATTERED SHOWERS AND THUNDERSTORMS. THE LAST FRONTAL BOUNDARY WILL STALL IN PROXIMITY OF THE S-SHORELINE OF NEW ENGLAND FOR THE REMAINDER OF THE WEEK BECOMING A FOCUS FOR ADDITIONAL WET-WEATHER. ALL OF THIS LOOKS TO CLEAR OUT BY THE WEEKEND ALLOWING FOR DRY AND SEASONABLE CONDITIONS. WILL POTENTIALLY SEE WET WEATHER RETURN ALONG WITH A WARM AND MUGGY PATTERN INTO EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... 7 PM UPDATE... MILD-MUGGY CONDITIONS PREVAILING OVERNIGHT. WILL SEE INCREASING MOISTURE WITHIN THE LOW-LEVELS APPROACH FROM THE SW PARENT WITH THE LIFTING WARM-FRONT AS A MID-LEVEL RIDGE OF HIGH PRESSURE AND DRIER AIR ERODES TO THE E. ACTING AS A BLANKET...LOWS THIS EVENING SHOULD BE MILD WITH VALUES AROUND THE MID- TO UPPER-60S...WARMER MORE SO IN SW NEW ENGLAND WHERE LOWER CLOUDS ARE EXPECTED INTO THE MORNING HOURS AS THERE IS A GREATER PROBABILITY OF INCREASING H975 MOISTURE. SOME CONCERN OVER PATCHY FOG MAINLY FOR THE S/SE-COAST WHERE DEWPOINTS PRESENTLY ARE IN THE MID- TO UPPER-60S AND S-WINDS CONTINUE TO SLOWLY ADVECT HIGHER DEWPOINT AIR NORTHWARD. LESSER CONFIDENCE ACROSS THE INTERIOR CONSIDERING FORECAST LOWS AND CROSSOVER THRESHOLDS AS MANY LOCALES MIXED OUT WELL TODAY WITH DEWPOINTS AROUND THE UPPER-50S...THOUGH DEWPOINTS HAVE REBOUNDED NICELY. MAY NEED TO KEEP AN EYE ON THIS. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/... TOMORROW INTO TOMORROW NIGHT... WARM FRONT WILL LIFT NORTHWARD TOMORROW PUTTING SOUTHERN NEW ENGLAND INTO A THE WARM/MOIST AIRMASS. A WEAK SHORTWAVE ALOFT WILL TRIGGER A FEW SCT SHOWERS WILL DEVELOP ACROSS THE REGION AFTER 11 AM LASTING INTO THE EVENING HOURS. MU CAPE VALUES COULD INCREASE TO 1500 J/KG AND WITH 20-30 KT SHEAR COULD SEE SOME STRONG STORMS. HAVE A VERY LOW CONFIDENCE ON IF ANY WOULD BE COME SEVER. LIMITING FACTOR IS THE LAPSE RATES AND THE CLOUD COVER...WHICH WOULD LIMIT THE AMOUNT OF INSTABILITY THAT COULD DEVELOP. YET PWAT VALUES ARE OVER 1.5 INCHES AND WITH WARM RAIN CORE PROCESSES...COULD SEE SOME HEAVY DOWNPOURS WITH PERHAPS URBAN/POOR DRAINAGE FLOODING. AS 850 MB TEMPS WARM TO 16C AND WITH DEWPOINTS REACHING CLOSE TO 70F...ANTICIPATE A WARM/MUGGY DAY. CONVECTION WILL BEGIN TO WIND DOWN BY THE EVENING HOURS AS HEATING IS LOST AND WE ARE ON THE BACKSIDE OF THE SHORTWAVE. SOUTHWESTERLY FLOW AHEAD OF AN APPROACHING COLD FRONT WILL KEEP THE REGION IN WARM/MOIST FLOW. THIS WILL ALLOW FOR FOG TO DEVELOP ESP ALONG THE SOUTH COAST. OVERNIGHT TEMPS WILL WILL BE MILD WITH SEVERAL PLACES ONLY DROPPING INTO THE LOW 70S. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... */ HIGHLIGHTS... - SCATTERED SHOWERS / THUNDERSTORMS FOR WEDNESDAY - CONTINUED PERIODS OF WET WEATHER INTO THE END OF THE WEEK - LOOKING DRY AND SEASONABLE FOR THE WEEKEND - A POSSIBLE RETURN OF A WARM-WET-MUGGY PATTERN NEXT WEEK */ DISCUSSION... WEDNESDAY: SKEPTICAL ON COLD FRONT TIMING. FEEL IT WILL SLOW AS IT SWEEPS S/E WITH ATTENDANT MID-LEVEL ENERGY AWAY FROM FASTER MID- TO UPPER-LEVEL FLOW...RUNNING UP AGAINST THE OFFSHORE BERMUDA HIGH. EXPECTATION THAT THE FRONT WILL ENTER S NEW ENGLAND AROUND THE 11A-2P TIMEFRAME SLOWING UP TOWARDS S/E NEW ENGLAND AROUND 2P-5P. HIGHER CONFIDENCE WITH SREF-PROBS OVER DETERMINISTIC SOLUTIONS. THUS CONSIDERING A HIGH THETA-E / INSTABILITY ENVIRONMENT ALONG AND AHEAD OF THE COLD FRONT WITHIN A WEAK-SHEAR ENVIRONMENT WITH VECTOR- ORIENTATION NOT OVERTLY PERPENDICULAR TO THE COLD FRONT. DO EXPECT SCATTERED ACTIVITY WITH PLAUSIBLE LINE-ECHO WAVE PATTERNS ESPECIALLY FOR SE NEW ENGLAND WHERE THERE IS A GREATER RESIDENCY TIME FOR THE ENVIRONMENT TO DESTABILIZE AND THERE IS ENOUGH SHEAR. THINK FORCING IS NOT IN QUESTION ALONG THE FRONT AS LOW- TO MID-LEVEL FLOW IS ALSO PERPENDICULAR TO THE FRONT. ALSO AM NOT THINKING ANYTHING SEVERE. MAYBE STRONG. LAPSE RATES ARE FAIRLY POOR ALOFT BASED ON A CONSENSUS OF FORECAST GUIDANCE. MAINLY FOCUSED ON GREATER AREAL COVERAGE OF ACTIVITY MORE SO THAN THE NAM/GFS DETERMINISTIC SUGGEST. AND WITH PWATS ADVERTISED IN EXCESS OF 2-INCHES...THE BIGGEST THREAT IS HEAVY RAIN. WILL LEAN WITH LIKELY POPS ESPECIALLY FOR S/SE-PORTIONS OF S NEW ENGLAND. REST OF THE WEEK: CONTINUING WITH SREF-PROBS BELIEVE THE FRONTAL BOUNDARY WILL STALL SOMEWHERE IN PROXIMITY TO THE S-COAST OF NEW ENGLAND BECOMING THE FOCUS FOR ADDITIONAL WET-WEATHER AS MID-LEVEL IMPULSES TRAVEL THROUGH THE QUASI-ZONAL FLOW ALOFT THAT IS PARALLEL TO THE FRONT. LIKELY TO SEE THE FRONT WOBBLE WITH LATER FORECASTS. THOUGH OVERALL DO THINK INSTABILITY HOLDS MAINLY S WITH ONCE AGAIN THE MAIN THREAT BEING HEAVY RAIN. NEVERTHELESS CAN NOT RULE OUT A RUMBLE OF THUNDER. A CONSENSUS OF GUIDANCE HAS THE FLOW BEING OVERALL PROGRESSIVE DESPITE TRAINING OF DISTURBANCES. WAVES LOOK TO BE SPACED OUT ENOUGH TO YIELD A LOW CONFIDENCE CONCERNING ANY FLOODING. JUST LOOKING LIKE A WET PATTERN WITH PERHAPS WARM-MUGGY CONDITIONS DEPENDING ON THE ORIENTATION AND PROXIMITY OF THE STALLED FRONTAL BOUNDARY. WEEKEND: BOTH DETERMINISTIC / ENSEMBLE GUIDANCE IN GOOD AGREEMENT OF THE TROUGH PATTERN LIFTING E. WITHIN THE W-PERIPHERY ALONG WITH RISING HEIGHTS EXPECT A SURFACE REFLECTION OF HIGH PRESSURE. DEEP-LAYER NORTHERLY WINDS SHOULD USHER DRIER AND MORE SEASONABLE CONDITIONS SOUTHWARD...SO LOOKS LIKE A BREAK FROM THE WARM-MUGGY PATTERN. EARLY NEXT WEEK: APPEARS THE TROUGH PATTERN RETURNS BASED ON ENSEMBLE MEANS. A LIKELY RETURN TO WARM-MUGGY CONDITIONS AND AN ACTIVE WEATHER PATTERN. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH TUESDAY NIGHT/... TONIGHT...MODERATE CONFIDENCE. VFR. MONITORING TERMINALS S/W FOR POSSIBLE MVFR-IFR CIGS AND VSBY COMBINATION. POSSIBLE FOG DEVELOPMENT WITH HIGHER CONFIDENCE OVER THE IMMEDIATE S/SE-SHORELINE. LIGHT SOUTHERLY WINDS. TUESDAY...HIGH CONFIDENCE. MVFR-IFR CIGS AND ANY FOG LIFT TO HIGH-END MVFR / LOW-END VFR. -SHRA/-TSRA DEVELOPING OVER W/SW-TERMINALS BY AFTERNOON. SEA- BREEZES DURING THE MORNING WILL ERODE WITH INCREASING S-WINDS GUSTING UP TO 25 KTS POSSIBLE ALONG THE S-COAST. TUESDAY NIGHT...MODERATE CONFIDENCE. CONDITIONS POSSIBLY DROPPING BACK TO MVFR-IFR ALONG WITH THE POTENTIAL FOR PATCHY FOG. KBOS TERMINAL...HIGH CONFIDENCE IN TAF. SEA-BREEZE DURING THE MORNING WILL ERODE BY AFTERNOON TUESDAY PER INCREASING S-WINDS. KBDL TERMINAL...HIGH CONFIDENCE IN TAF. PATCHY FOG IS POSSIBLE TONIGHT. LOW RISK OF A -TSRA TOMORROW AFTERNOON. OUTLOOK /WEDNESDAY THROUGH SATURDAY/... WEDNESDAY...MODERATE CONFIDENCE. MAINLY VFR. SCT SHRA/TSRA ESP S /SE-NEW ENGLAND. TEMPO MVFR-IFR WITH ANY WX. COLD FRONT PUSHES OFFSHORE LATE. SW-WINDS SHIFT NORTHERLY. THURSDAY AND FRIDAY...LOW CONFIDENCE. LOW-END VFR / MVFR. FRONT STALLS IN PROXIMITY TO S-SHORE OF NEW ENGLAND. FOCUS OF ADDITIONAL -RA / RA. VARIABLE WINDS. SATURDAY...MODERATE CONFIDENCE. VFR. N/NW-WINDS. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT-TERM /THROUGH TUESDAY NIGHT/...HIGH CONFIDENCE. 7 PM UPDATE... QUIET BOATING WEATHER TONIGHT. PATCHY FOG POSSIBLE OVER S-WATERS. OTHERWISE SEAS WILL BEGIN TO BUILD TUESDAY AS A WARM FRONT MOVES OVER THE WATERS. COULD SEE SOME LOW END SCA DURING THE AFTERNOON WITH SOUTHERLY WIND GUSTS NEAR 25 KTS AND SEAS 4-5FT. ALTHOUGH MARGINAL...FELT IT WAS BEST DUE TO ALL OF THE RECREATIONAL BOATERS ACROSS THE WATERS THIS WEEK. AFTER SUNSET...S-WINDS WILL DIE DOWN BUT COULD SEE A CHOP ALONG THE WATERS OVERNIGHT. PATCHY DENSE FOG COULD ALSO REDEVELOP OVER THE WATERS. OUTLOOK /WEDNESDAY THROUGH SATURDAY/... WEDNESDAY...MODERATE CONFIDENCE. SCATTERED SHOWERS AND THUNDERSTORMS FOR THE WATERS INTO THE AFTERNOON HOURS AND CONTINUING INTO THE EVENING. BREEZY SW-WINDS AHEAD OF THE FRONT BECOMING VARIABLE AS THE FRONT STALLS IN PROXIMITY TO THE S-COAST. WAVES HOLDING BELOW 5-FEET. PATCHY DENSE FOG POSSIBLE AT TIMES. THURSDAY AND FRIDAY...LOW CONFIDENCE. FRONT STALLS W TO E ACROSS THE S-WATERS. PERIODS OF WET WEATHER. VARIABLE WINDS THROUGHOUT KEEPING WAVES BELOW 5-FEET. PATCHY DENSE FOG POSSIBLE AT TIMES. SATURDAY...MODERATE CONFIDENCE. HIGH PRESSURE BUILDING INTO THE WATERS. N/NW-WINDS PERHAPS BLUSTERY AT TIMES. WILL HOLD WAVES BELOW 5-FEET. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. RI...NONE. MARINE...SMALL CRAFT ADVISORY FROM 2 PM TO 9 PM EDT TUESDAY FOR ANZ230>237-251. && $$ SYNOPSIS...DUNTEN/SIPPRELL NEAR TERM...DUNTEN/SIPPRELL SHORT TERM...DUNTEN LONG TERM...SIPPRELL AVIATION...DUNTEN/SIPPRELL MARINE...DUNTEN/SIPPRELL

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